1  #include <stdlib.h>
       2  #include <unistd.h>
       3  
       4  int
       5  main ()
       6  {
       7    #pragma omp parallel
       8    #pragma omp single
       9    {
      10      int x = 1, y = 2;
      11      #pragma omp taskgroup
      12      {
      13        #pragma omp task shared (x) depend(in: x)
      14        {
      15  	usleep (10000);
      16  	if (x != 1)
      17  	  abort ();
      18        }
      19        #pragma omp taskgroup
      20        {
      21  	#pragma omp task shared (x) depend(in: x)
      22  	{
      23  	  usleep (15000);
      24  	  if (x != 1)
      25  	    abort ();
      26  	}
      27  	#pragma omp task shared (y) depend(inout: y)
      28  	{
      29  	  if (y != 2)
      30  	    abort ();
      31  	  y = 3;
      32  	}
      33  	#pragma omp taskgroup
      34  	{
      35  	  #pragma omp task shared (x) depend(in: x)
      36  	  {
      37  	    usleep (13000);
      38  	    if (x != 1)
      39  	      abort ();
      40  	  }
      41  	  #pragma omp taskgroup
      42  	  {
      43  	    #pragma omp task shared (x) depend(out: x)
      44  	    x = 2;
      45  	  }
      46  	}
      47        }
      48      }
      49    }
      50    return 0;
      51  }